Interactive displays present information and/or vouchers, typically in the form of an optical pattern. These optical patterns comprise spatial codes that can be captured by a portable device. A user of a portable device holds the portable device in the vicinity of the optical pattern and uses a camera incorporated within the portable device to capture an image of the optical pattern from the interactive display. The captured optical pattern is then decoded by the portable device to create an electronic voucher, which is then used by that portable device.
The electronic voucher typically includes a Uniform Resource Locator (URL) that the portable device loads into its Web browser. This allows the user to access an offer, a service, or the like, without having to remember any special codes or type copious amounts of data into a keyboard on the portable device.
These interactive displays are very useful for presenting offers to passers by, but there are some problems associated with these interactive displays. The information presented can be used multiple times, particularly if someone transmits an image of the optical pattern to a friend or loads the image of the optical pattern onto a Web site for other people to download and use. Furthermore, the interactive display has no information about how many times an optical pattern has been captured by passers by.